Check if given Fortran source compiles and links into an executable.
check_fortran_source_compiles(<code> <resultVar>
[FAIL_REGEX <regex>...]
[SRC_EXT <extension>]
)
Checks that the source supplied in <code> can be compiled as a Fortran source file and linked as an executable. The <code> must be a Fortran program containing at least an end statement–for example:
check_fortran_source_compiles("character :: b; error stop b; end" F2018ESTOPOK SRC_EXT F90)
This command can help avoid costly build processes when a compiler lacks support for a necessary feature, or a particular vendor library is not compatible with the Fortran compiler version being used. This generate-time check may advise the user of such before the main build process. See also the check_fortran_source_runs() command to actually run the compiled code.
The result will be stored in the internal cache variable <resultVar>, with a boolean true value for success and boolean false for failure.
If FAIL_REGEX is provided, then failure is determined by checking if anything in the output matches any of the specified regular expressions.
By default, the test source file will be given a .F file extension. The SRC_EXT option can be used to override this with .<extension> instead– .F90 is a typical choice.
The underlying check is performed by the try_compile() command. The compile and link commands can be influenced by setting any of the following variables prior to calling check_fortran_source_compiles():
The check is only performed once, with the result cached in the variable named by <resultVar>. Every subsequent CMake run will re-use this cached value rather than performing the check again, even if the <code> changes. In order to force the check to be re-evaluated, the variable named by <resultVar> must be manually removed from the cache.